2025/02/13 by Duan, Guijing, Liao, Zhiguang, Chen, Lei +3 · 4 citations
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2502.09195
The recent discovery of superconductivity in La3Ni2O7 raises key questions about its mechanism and the nature of pairing symmetry. This system is believed to be described by a bilayer two-orbital Hubbard model. The considerations of orbital-selective Mott correlations motivate a bilayer two-orbital t-J model and, accordingly, we study the superconducting pairing in this model. We obtain an overall phase diagram of superconductivity, where the leading channel has either extended s-wave or dx2-y2-wave symmetry. Our analysis highlights how the orbital-selective correlations affect the superconducting pairing via the interlayer exchange couplings and low-energy electronic structure. In particular, we find that the dominant orbital for the pairing may change between z2 and x2-y2 when the position of the bonding z2 band is varied by tuning either the c-axis lattice constant or electron concentration strength. We discuss the implications of these results for the superconductivity in both bulk La3Ni2O7 and its thin film counterpart.